JP5744803B2 - Sheet conveying apparatus and image forming apparatus provided with the same - Google Patents

Description

  The present invention relates to a sheet conveying apparatus that conveys a sheet, and an image forming apparatus including the sheet conveying apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus that forms an image on a sheet, a toner image is formed on a photosensitive drum of an image forming unit, and the toner image is transferred to the sheet at a transfer nip portion. The image forming apparatus further includes a fixing unit, and the sheet on which the toner image is transferred is subjected to a fixing process in the fixing unit and then discharged.

  In the image forming apparatus as described above, a paper feeding device for feeding a sheet to the transfer nip portion is disposed. The sheet feeding device includes a sheet cassette and a manual feed tray. The first sheet conveyance path extending from the sheet cassette and the second sheet conveyance path extending from the manual feed tray are merged at the conveyance path merging portion, and then reach the transfer nip portion. Therefore, in order to selectively communicate one of the first and second sheet conveyance paths with the transfer nip portion, a swingable switching guide member is disposed at the conveyance path junction.

  Patent Document 1 discloses an elongate switching guide member in a cross-sectional view in a direction crossing the sheet conveyance direction. The sheet conveyance path is switched by turning the upper end side of the switching guide member around the fulcrum arranged at the lower end of the switching guide member.

JP-A-4-64540

  In recent years, with the miniaturization of image forming apparatuses, it is desired to reduce the size of the paper feeding apparatus as described above. As a result, it is desirable that the space occupied by the conveyance path junction where the plurality of sheet conveyance paths are merged is reduced as much as possible. In addition, since the sheet conveyance path itself is designed to be compact, the curvature of the sheet conveyance path is often set large in the conveyance path junction.

  Since the switching guide member described in Patent Document 1 is rotated around a fulcrum disposed at the lower end, the movable range of the guide member is limited. For this reason, the guide member may not be able to sufficiently guide the sheet along the curved shape of the sheet conveyance path having a large curvature.

  The present invention has been made in view of the above problems, and in a sheet conveying apparatus including a guide member that switches a sheet conveying path and an image forming apparatus including the guide member, a movable range is set large, and the shape of the sheet conveying path is set. An object is to provide a guide member along.

A sheet conveying apparatus according to an aspect of the present invention is provided in a housing, a first conveying path that is disposed in the housing, the first sheet is conveyed in a first direction, and the housing. The second sheet is conveyed in a second direction intersecting the first direction and merged with the first conveyance path, the second conveyance path merged with the first conveyance path, and the first conveyance path and the second conveyance path. A first position disposed in a portion for guiding the first sheet in a third direction intersecting the first direction and the second direction; and the second sheet in the first direction and the first direction. Between the second position guided in the third direction intersecting the direction of 2 and a guide member capable of changing the position, and opposed to the guide member, and between the guide member and the guide member It comprises a wall portion which forms part of the second conveyance path, and has a cover member capable of opening and closing with respect to the housing The guide member, when viewed in cross-section perpendicular to the sheet width direction of the first sheet consists of elongated, with a longitudinal central portion or fulcrum portion disposed in the vicinity of the elongated, the fulcrum The position can be changed by rotating about a portion, and when the cover member is open, the guide member is disposed at the first position, and a part of the first transport path is part of the housing. The guide member is exposed to the outside of the body, and with the change of the cover member from the closed state to the open state, the guide member is retracted to expose the first transport path to the outside of the housing rather than the first position. Rotated to a position, disposed on the cover member, abuts on the guide member as the cover member changes from an open state to a closed state, and rotates the guide member from the retracted position to the first position. The protrusion to be moved Characterized in that it.

According to this configuration, the guide member guides the first sheet conveyed in the first direction along the first conveyance path in the third direction at the first position. The guide member guides the second sheet conveyed in the second direction along the second conveyance path in the third direction at the second position. The guide member is rotated around a fulcrum portion arranged at the longitudinal center or in the vicinity thereof. For this reason, when switching the sheet conveyance path in which the guide member is guided in the third direction between the first conveyance path and the second conveyance path, a fulcrum is disposed at one end in the longitudinal direction of the guide member. In comparison, a large movable range of the guide member is ensured. Further, according to this configuration, in the open state of the cover member, the wall portion is separated from the guide member, and therefore a part of the second transport path is opened to the outside of the housing. Further, by arranging the guide member at the first position, a part of the first transport path is exposed to the outside of the housing. For this reason, even if the sheet is jammed in the first conveyance path or the second conveyance path around the guide member, the sheet is easily removed. Further, according to this configuration, when the cover member is opened, the guide member is rotated to the retracted position that exposes the first transport path to the outside of the housing rather than the first position. For this reason, the first conveyance path is further opened, and the jammed sheet is easily removed. Further, the guide member can be returned from the retracted position to the first position by the protrusion of the cover member.

  In the above configuration, the wall surface of the guide member that extends upstream of the fulcrum portion in the third direction is adapted to move the first transport path and the guide member with the rotation of the guide member. It is desirable to define a part of the second transport path.

  According to this configuration, when the guide member is rotated about the fulcrum portion, the wall surface extending upstream in the third direction from the fulcrum portion of the guide member is the first conveyance path and the second conveyance. Define a portion of the path. For this reason, it becomes possible for a guide member to guide a sheet suitably along the shape of the selected sheet conveyance path.

  In the above-described configuration, the guide member is disposed at the first position by its own weight or the urging force of the urging member provided at the fulcrum portion, and the leading end of the second sheet conveyed through the second conveyance path. It is desirable that the guide member moves from the first position to the second position when the portion abuts on the guide member.

  According to this configuration, the guide member is stably disposed at the first position by its own weight or the urging force of the urging member provided at the fulcrum portion. For this reason, the 1st sheet conveyed by the 1st conveyance path can be correctly guided to the 3rd direction. Furthermore, the guide member moves from the first position to the second position when the leading end of the second sheet conveyed through the second conveyance path contacts the guide member. For this reason, even if it is the state where the guide member is arranged in the 1st position, the 2nd sheet conveyed by the 2nd conveyance way can be correctly guided to the 3rd direction.

  In the above configuration, it is preferable that the tip portion of the second sheet abuts on a wall surface of the guide member on the downstream side of the fulcrum portion.

  According to this configuration, the guide member is reliably moved from the first position to the second position by the front end portion of the second sheet contacting the wall surface of the guide member on the downstream side of the fulcrum portion.

  In the above configuration, the image forming apparatus further includes: a sheet stacking unit on which the first sheet is stacked; and a manual feed tray on which the second sheet is mounted, and the first transport path extends from the sheet stacking unit to the guide. It is preferable that the first sheet is transported to a member, and the second transport path is a transport path that transports the second sheet from the manual feed tray to the guide member.

  According to this configuration, the sheet conveyance path through which the guide member is guided in the third direction includes the first conveyance path extended from the sheet stacking unit and the second conveyance path extended from the manual feed tray. When switching between them, the movable range of the guide member is ensured larger than in the case where the fulcrum is arranged at one end of the guide member.

  In the above configuration, the image forming apparatus further includes a third conveyance path that extends from between the first conveyance path and the second conveyance path toward the guide member, and the guide member includes the first position and the first conveyance path. It is desirable to further include a third position between the second position and the third sheet for guiding the third sheet conveyed through the third conveyance path in the third direction.

  According to this configuration, the guide member can guide the third sheet conveyed through the third conveyance path in the third direction in addition to the first conveyance path and the second conveyance path.

  An image forming apparatus according to another aspect of the present invention includes the sheet conveying device according to any one of the above, an image forming unit that forms an image on the first sheet and the second sheet, and the guide member. And a fourth transport path through which the first sheet or the second sheet guided in the direction of 3 is transported to the image forming unit.

  According to this configuration, when the sheet conveyance path in which the guide member is guided in the third direction is switched between the first conveyance path and the second conveyance path, a fulcrum is disposed at one end of the guide member. In comparison, a large movable range of the guide member is ensured. For this reason, even when the first conveyance path and the second conveyance path are merged from directions separated from each other by a large angle, the first sheet or the second sheet is directed to the image forming unit by the guide member. It is stably guided to the fourth transport path.

  According to the present invention, in a sheet conveying apparatus including a guide member that switches a sheet conveying path and an image forming apparatus including the guide member, a guide member is provided along the shape of the sheet conveying path.

1 is a perspective view of an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view of an image forming apparatus according to an embodiment of the present invention. 1 is an internal cross-sectional view of an image forming apparatus according to an embodiment of the present invention. 1 is an enlarged cross-sectional view of a part of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of a conveyance junction portion of the image forming apparatus according to the embodiment of the present invention. In the image forming apparatus according to the embodiment of the present invention, it is a cross-sectional view showing a state in which a housing opening and closing unit is opened. FIG. 2 is an enlarged cross-sectional view of a part of an image forming apparatus compared with an embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of a part of a conveyance junction of an image forming apparatus compared with an embodiment of the present invention. FIG. 6 is a cross-sectional view illustrating a state where a housing opening / closing part is opened in an image forming apparatus according to another embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 are external perspective views of an image forming apparatus 1 according to an embodiment of the present invention. FIG. 3 is an internal cross-sectional view of the image forming apparatus 1. The image forming apparatus 1 shown in FIGS. 1 to 3 is a so-called monochrome multifunction peripheral. However, in other embodiments, the image forming apparatus is a color multifunction peripheral, a color printer, a facsimile apparatus, or the like. Other devices for forming a sheet on the sheet may be used. Note that the terms used in the following description, such as “up”, “down”, “front”, “rear”, “left” and “right”, are merely for the purpose of clarifying the description. There is no limitation on the principle of the image forming apparatus. In the following description, the term “sheet” means copy paper, coated paper, OHP sheet, cardboard, postcard, tracing paper, other sheet material subjected to image forming processing, or any processing other than image forming processing. Means the sheet material to receive.

  The image forming apparatus 1 includes a main housing 2 having a substantially rectangular parallelepiped shape. The main casing 2 includes a substantially rectangular parallelepiped lower casing 21 (casing), a substantially rectangular parallelepiped upper casing 22 disposed above the lower casing 21, a lower casing 21, and an upper casing 22. And a connecting housing 23 for connecting the two. The connection housing 23 extends along the right edge and the back edge of the main housing 2. The sheet S subjected to the printing process is discharged into the discharge space 24 surrounded by the lower casing 21, the upper casing 22 and the connecting casing 23. In particular, in the present embodiment, the sheet S is discharged to a paper discharge unit 241 disposed on the upper surface of the lower housing 21 and a paper discharge tray 242 (FIG. 3) disposed above the paper discharge unit 241. The

  The operation unit 221 disposed in the front direction of the upper housing 22 includes an LCD touch panel 222, for example. The operation unit 221 is formed so as to be able to input information related to the image forming process. For example, the user can input the number of sheets to be printed, the print density, and the like through the LCD touch panel 222. Housed in the upper housing 22 are mainly an apparatus for reading an image of a document and an electronic circuit that controls the entire image forming apparatus 1.

  A pressing cover 223 disposed on the upper housing 22 is used for pressing the document. The presser cover 223 is attached to the upper housing 22 so as to be rotatable up and down. The user rotates the holding cover 223 upward to place the document on the upper housing 22. Thereafter, the user can operate the operation unit 221 to read an image of the document on a device provided in the upper housing 22.

  A manual feed tray 240 is disposed on the right side surface of the lower housing 21. The manual feed tray 240 can be rotated up and down on the upper end 240B side with the lower end 240A (FIG. 3) as a fulcrum. The user can place the sheet S on the manual feed tray 240 when the manual feed tray 240 is rotated downward and the manual feed tray 240 is in a position protruding to the right of the lower housing 21. The sheet S (sheet S2, second sheet) on the manual feed tray 240 is pulled into the lower housing 21 based on an instruction input by the user through the operation unit 221, and then subjected to image forming processing. It is discharged into the discharge space 24. In addition, an internal space S in which various devices described later are arranged is formed inside the lower housing 21 (FIG. 3).

  The image forming apparatus 1 includes a paper feeding device 10, a registration roller pair 116, and an image forming unit 120. The sheet feeding device 10 includes a cassette 110 (sheet stacking unit), a sheet feeding unit 11, a second sheet feeding roller 114, and a conveyance junction unit 101.

  The cassette 110 accommodates the sheet S (sheet S1, first sheet) therein. The cassette 110 can be pulled out from the lower housing 21 in the front direction (the front side in FIG. 3). The sheet S accommodated in the cassette 110 is sent upward in the lower housing 21. Thereafter, the sheet S is subjected to an image forming process in the lower housing 21 based on an instruction input by the user through the operation unit 221, and is discharged into the discharge space 24. The cassette 110 includes a lift plate 111 that supports the sheet S. The lift plate 111 is inclined so as to push up the leading edge of the sheet S upward.

  The paper feed unit 11 includes a pickup roller 112 and a first paper feed roller 113. The paper feeding unit 11 sends out the sheet S of the cassette 110 to the sheet conveyance path PP. The sheet conveyance path PP is a conveyance path arranged so as to pass from the paper feeding unit 11 via the registration roller pair 116 to the transfer position TP arranged in the image forming unit 120.

  The pickup roller 112 is disposed on the leading edge of the sheet S pushed upward by the lift plate 111. When the pickup roller 112 rotates, the sheet S is sent out from the cassette 110 to the first paper feed roller 113.

  The first paper feed roller 113 is disposed downstream of the pickup roller 112 in the sheet conveyance direction. The first paper feed roller 113 further feeds the sheet S downstream in the sheet conveyance direction. A counter roller 115 is disposed below the first paper feed roller 113 so as to face the first paper feed roller 113. A sheet feeding nip through which the sheet S is fed is formed at the facing portion of the first sheet feeding roller 113 and the facing roller 115.

  The second paper feed roller 114 is disposed inside the lower end 240 </ b> A of the manual feed tray 240. The second paper feed roller 114 conveys the sheet on the manual feed tray 240 into the lower housing 21. The user can selectively use the sheet S accommodated in the cassette 110 or the sheet S placed on the manual feed tray 240.

  The conveyance junction unit 101 is a portion where a sheet conveyance path extending from the cassette 110 and a sheet conveyance path extending from the manual feed tray 240 merge. The conveyance junction unit 101 will be described in detail later.

  The registration roller pair 116 defines the position of the sheet in a direction orthogonal to the sheet conveyance direction. Thereby, the position of the image formed on the sheet S is adjusted. The registration roller pair 116 forms a nip portion between the rollers. The registration roller pair 116 conveys the sheet S to the image forming unit 120 in accordance with the timing at which the toner image is transferred to the sheet S in the image forming unit 120. The registration roller pair 116 has a function of correcting skew (skew) of the sheet S.

  The image forming unit 120 includes a photosensitive drum 121, a charger 122, an exposure device 123, a developing device 124, a toner container 125, a transfer roller 126, a cleaning device 35, and a static eliminator 50.

  The photosensitive drum 121 has a substantially cylindrical shape. The photosensitive drum 121 has an electrostatic latent image formed on its peripheral surface and carries a toner image corresponding to the electrostatic latent image.

  The charger 122 is applied with a predetermined voltage and charges the peripheral surface of the photosensitive drum 121 substantially uniformly. The exposure device 123 irradiates the peripheral surface of the photosensitive drum 121 charged by the charger 122 with laser light. The laser light is emitted in accordance with image data output from an external device (not shown) such as a personal computer that is communicably connected to the image forming apparatus 1. As a result, an electrostatic latent image corresponding to the image data is formed on the peripheral surface of the photosensitive drum 121.

  The developing device 124 supplies toner to the peripheral surface of the photosensitive drum 121 on which the electrostatic latent image is formed. The toner container 125 supplies toner to the developing device 124. The toner container 125 supplies toner to the developing device 124 sequentially or as necessary. When the developing device 124 supplies toner to the photosensitive drum 121, the electrostatic latent image formed on the peripheral surface of the photosensitive drum 121 is developed (visualized). As a result, a toner image is formed on the peripheral surface of the photosensitive drum 121. The developing device includes a developing roller 124A that carries toner on the peripheral surface. The developing roller 124A is disposed to face the photosensitive drum 121 at the developing position. The developing roller 124 </ b> A is rotated and supplies toner to the photosensitive drum 121.

  The transfer roller 126 is disposed to face the peripheral surface of the photosensitive drum 121 at the transfer position TP. The transfer roller 126 is rotationally driven in the same direction as the photosensitive drum 121 at the transfer position TP. The toner image formed on the peripheral surface of the photosensitive drum 121 is transferred to the sheet S at the transfer position TP.

  The cleaning device 35 removes the toner remaining on the peripheral surface of the photosensitive drum 121 after the toner image is transferred to the sheet S. The static eliminator 50 irradiates the photosensitive drum 121 whose peripheral surface is cleaned by the cleaning device 35 with predetermined static elimination light. As a result, the potential on the peripheral surface of the photosensitive drum 121 is made uniform.

  After being cleaned by the cleaning device 35, the peripheral surface of the photosensitive drum 121, which has been neutralized by the static eliminator 50, passes again below the charger 122 and is uniformly charged. Thereafter, the above-described toner image is newly formed.

  The image forming apparatus 1 further includes a fixing device 130 that fixes the toner image on the sheet S downstream of the image forming unit 120 in the transport direction. The fixing device 130 includes a heating roller 131 that melts the toner on the sheet S and a pressure roller 132 that causes the sheet S to adhere to the heating roller 131. When the sheet S passes between the heating roller 131 and the pressure roller 132, the toner image is fixed on the sheet S.

  The image forming apparatus 1 includes a transport roller pair 133 disposed downstream of the fixing device 130, a switching unit 70 disposed downstream of the transport roller pair 133, a lower discharge roller 134, an upper discharge roller 135, Is further provided. The conveyance roller pair 133 conveys the sheet S subjected to the fixing process by the fixing device 130 to the downstream side in the sheet conveyance direction. The switching unit 70 has a function of switching the conveyance direction of the sheet S on the downstream side of the conveyance roller pair 133 in the sheet conveyance direction. The lower discharge roller 134 is disposed on the left side of the switching unit 70 and discharges the sheet S conveyed by the conveyance roller pair 133 to the paper discharge unit 241. The upper discharge roller 135 is disposed above the lower discharge roller 134 and discharges the sheet S conveyed by the conveyance roller pair 133 to a discharge tray 242 mounted above the discharge unit 241.

  Next, with reference to FIG. 4 and FIG. 5, the conveyance joining part 101 which concerns on this embodiment is explained in full detail. FIG. 4 is an enlarged cross-sectional view of a part of the image forming apparatus 1 including the paper feeding device 10, and FIG. 5 is a cross-sectional view in which the periphery of the conveyance junction 101 is further enlarged in FIG. 4. In the present embodiment, in the conveyance junction unit 101, three sheet conveyance paths (first sheet conveyance path P1, second sheet conveyance path P2, and third sheet conveyance path P3) are merged.

  The first sheet conveyance path P1 (first conveyance path) is a conveyance path through which the sheet S1 (first sheet) fed from the cassette 110 is conveyed. The sheet S1 is conveyed rightward and slightly upward along the first sheet conveyance path P1 (first direction). As described above, the sheet S1 passes through the sheet feeding nip between the first sheet feeding roller 113 and the opposing roller 115, and is carried into the conveyance junction unit 101 (arrow D1 in FIG. 5). Note that a cover member 118 is disposed on the downstream side of the opposing roller 115 in the sheet conveyance direction. The cover member 118 includes a guide part 118A and a protection part 118B. The guide portion 118A is disposed at the upper end portion of the cover member 118, and demarcates a part of the first sheet conveyance path P1. That is, the guide portion 118A extends along the conveyance direction of the sheet S1 in the first sheet conveyance path P1. The protection unit 118B is provided continuously with the guide unit 118A, and is disposed along the circumferential surface at a distance from the circumferential surface of the facing roller 115. The protection unit 118 </ b> B provides scratches and foreign matter on the peripheral surface of the opposing roller 115 when the conveyance junction unit 101 is exposed to the outside of the image forming apparatus 1 as described later for the recovery operation of the sheet jam in the conveyance junction unit 101. Prevents scrambles.

  The second sheet conveyance path P2 (second conveyance path) is a conveyance path through which the sheet S2 (second sheet) fed from the manual feed tray 240 is conveyed. The sheet S2 is conveyed in a direction leftward and upward along the second sheet conveyance path P2 (a direction intersecting the first direction, a second direction). Further, the second sheet conveyance path P2 is merged with the first sheet conveyance path P1 in the conveyance junction unit 101. A counter pad 117 is disposed below the second paper feed roller 114 described above.

  The counter pad 117 is a member that forms a paper feed nip with the second paper feed roller 114. The counter pad 117 is arranged to face the second paper feed roller 114 on the left and below the second paper feed roller 114. The counter pad 117 includes a pad base material portion 117A, a pad tip portion 117B, and a pad rubbing portion 117C. The pad base material portion 117 </ b> A is a main body portion of the counter pad 117 and is a plate-like member that is disposed to face the second paper feed roller 114. The pad tip portion 117B extends from the upper end portion of the pad base material portion 117A toward the left. The pad rubbing portion 117C is fixed to the upper surface portion of the pad base material portion 117A. The pad rubbing portion 117 </ b> C is in contact with the peripheral surface of the second paper feed roller 114, and forms a paper feed nip with the peripheral surface of the second paper feed roller 114. A material having a high friction coefficient is used for the pad rubbing portion 117C in order to suitably separate the sheet S2 placed on the manual feed tray 240. With the rotation of the second paper feed roller 114, the sheet S2 passes between the second paper feed roller 114 and the pad rubbing portion 117C and is carried into the conveyance junction portion 101 (arrow D2 in FIG. 5). ).

  Further, the third sheet conveyance path P3 (third conveyance path) is a conveyance path that is disposed from the lower side to the upper side between the first sheet conveyance path P1 and the second sheet conveyance path P2. The third sheet conveyance path P3 is a conveyance path that reaches the conveyance junction 101 through the connection opening 21R shown in FIG. When a post-feed type paper feed cassette (not shown) is attached to the image forming apparatus 1 shown in FIG. 1 or FIG. 2, the sheet S3 (third sheet) fed from the paper feed cassette is It is carried into the connecting opening 21R and conveyed through the third sheet conveying path P3 (arrow D3 in FIG. 5).

  A guide member 90 is disposed at the joining portion of the above three sheet conveyance paths. The sheet S conveyed from any of the sheet conveyance paths is guided by the guide member 90 and is carried into the merging conveyance path 15 (FIG. 5) (fourth conveyance path). In other words, the guide member 90 guides the sheet S conveyed in the first sheet conveying path P1, the second sheet conveying path P2, and the third sheet conveying path P3 upward (in the first direction and the first direction). Direction intersecting the direction 2, the third direction). The merge conveyance path 15 is defined by the first wall 150 on the left side and the second wall 151 on the right side. Then, the sheet S carried into the merging conveyance path 15 reaches the registration roller pair 116 and is conveyed to the image forming unit 120.

  Referring to FIG. 5, the guide member 90 is a plate-like member having an elongated shape in a cross-sectional view orthogonal to the conveyance direction of the sheet S and extending in the front-rear direction (direction orthogonal to the paper surface of FIG. 5). is there. The guide member 90 includes a fulcrum part 901, a guide part 901A, and a contact part 901B.

  The fulcrum part 901 is arranged at the center part in the longitudinal direction of the guide member 90 in the sectional view. The fulcrum portion 901 serves as a fulcrum for the rotation of the guide member 90. The guide member 90 is rotated with the fulcrum portion 901 as a fulcrum, and the position of the guide member 90 can be changed between the first position 90A and the second position 90B in FIG. That is, at the first position 90A, the upper end portion of the guide member 90 is disposed on the rightmost side. In the second position 90B, the upper end portion of the guide member 90 is disposed on the leftmost side. In addition, the position where the guide member 90 extends in the substantially vertical direction between the first position 90A and the second position 90B in the rotation of the guide member 90 is defined as the third position 90C. The

  The guide portion 901 </ b> A is a portion of the guide member 90 that extends upward from the fulcrum portion 901. The guide portion 901A has a shape that is slightly tapered toward the upper end. The guide portion 901A includes a left guide surface 902 and a right guide surface 903 which are a pair of side surfaces. The left guide surface 902 is the left side surface of the guide portion 901A. The right guide surface 903 is a right side surface of the guide portion 901A.

  The contact portion 901 </ b> B (projection) is a portion of the guide member 90 that extends below the fulcrum 901 (upstream in the third direction). Note that, in the abutting portion 901B, a region on the left side and close to the fulcrum portion 901 has a shape protruding outward. In the first position 90A of the guide member 90, the left guide surface upstream portion 90S, which is the wall surface of the raised portion, is disposed along the guide portion 118A of the cover member 118, and the first sheet conveyance path A part of P1 is defined. Furthermore, the second position 90 </ b> B of the guide member 90 is defined by the contact portion 901 </ b> B coming into contact with the pad tip portion 117 </ b> B of the counter pad 117 when the guide member 90 rotates. At this time, the right side portion of the contact portion 901B defines a part of the second sheet conveyance path P2. Further, the first position 90A of the guide member 90 is defined by the contact portion 901B (the lower end portion of the left guide surface upstream portion 90S) contacting the protection portion 118B of the cover member 118.

  Further, in the present embodiment, the center of gravity of the guide member 90 is set so that the guide member 90 is disposed at the first position 90A by the weight of the guide member 90. As another embodiment, when a helical spring (not shown) is arranged on the fulcrum 901 and no other external force is applied to the guide member 90, the guide member 90 is moved to the first position by the biasing force of the helical spring. It may be set to be arranged at 90A.

  A wall portion 119 is disposed on the right side of the guide member 90 so as to face the guide member 90. The wall portion 119 is integrally fixed to a case opening / closing portion 21A described later. The wall portion 119 defines a downstream end portion in the conveyance direction of the second sheet conveyance path P <b> 2 with the guide member 90.

  Next, the movement of the guide member 90 when a sheet is carried into the conveyance junction 101 from each sheet conveyance path will be described.

  When the sheet S1 accommodated in the cassette 110 is transported to the first sheet transport path P1, as described above, the guide member 90 is disposed at the first position 90A by its own weight. Therefore, the sheet S1 that has passed between the first paper feed roller 113 and the counter roller 115 slides on the guide portion 118A and the left guide surface upstream portion 90S, and the left guide surface of the guide member 90 at the first position 90A. 902 is guided upward. Then, the sheet S <b> 1 is conveyed from the merging / conveying unit 15 to the registration roller pair 116 while being rubbed against the second wall portion 151. Since the image forming apparatus 1 is more frequently fed from the sheet S1 stacked on the cassette 110 than the manual feed tray 240, the position where the guide member 90 is normally disposed is set to the first position 90A. As a result, the sheet S1 is stably conveyed.

  On the other hand, after the sheet S2 placed on the manual feed tray 240 passes between the second paper feed roller 114 and the counter pad 117, the sheet S2 is conveyed toward the guide member 90 disposed at the first position 90A by its own weight. Is done. At this time, in this embodiment, the leading end portion of the sheet S2 conveyed through the second sheet conveyance path P2 is in contact with the contact portion 90P above the fulcrum portion 901 in the right guide surface 903 of the guide member 90. In addition, the angle of the counter pad 117 (pad rubbing portion 117C) is set in advance. Therefore, the guide member 90 is rotated around the fulcrum portion 901 and disposed at the second position 90B when the leading end portion of the sheet S2 contacts the contact portion 90P. Thus, the sheet S2 is guided upward while sliding on the right guide surface 903 of the guide member 90 at the second position 90B. Then, the sheet S <b> 2 is conveyed from the merging / conveying unit 15 to the registration roller pair 116 while being rubbed against the first wall 150.

  Further, the sheet S3 fed from a not-shown post-feed type paper feed cassette is carried into the third sheet transport path P3 through the connection opening 21R (arrow D3 in FIG. 5). In the present embodiment, as in the case of the second sheet conveyance path P2, the right wall portion that defines the third sheet conveyance path P3 so that the leading end portion of the sheet S3 contacts the contact portion 90P of the guide member 90. The angle of a certain third wall portion 152 is set in advance. Then, the guide member 90 is rotated around the fulcrum portion 901 and disposed at the third position 90C when the leading end portion of the sheet S3 contacts the contact portion 90P. Thus, the sheet S3 is guided upward while rubbing against the right guide surface 903 of the guide member 90 at the third position 90C. Then, the sheet S3 is conveyed from the merging conveyance unit 15 to the registration roller pair 116 while passing between the first wall 150 and the second wall 151.

  As described above, according to the present embodiment, the sheet S conveyed from the first sheet conveyance path P1, the second sheet conveyance path P2, and the third sheet conveyance path P3 is stabilized by the rotation of the guide member 90. Then, it is guided to the merging and conveying unit 15. At this time, since the fulcrum of rotation of the guide member 90 is disposed at the center in the longitudinal direction of the guide member 90, the guide member 90 rotates with a large movable range in a space reduced as much as possible. Is possible. In particular, in the present embodiment, as shown in FIG. 5, the angle formed by the left guide surface 902 and the vertical direction at the first position 90A is 21 degrees. The angle formed between the right guide surface 903 and the vertical direction at the second position 90B is 29.8 degrees. In other words, the angle formed by the two sheet conveying directions switched by the guide member 90 reaches 50.8 degrees. For this reason, in the sheet feeding device 10 including the first sheet conveyance path P1 from the left to the conveyance merge unit 101 and the second sheet conveyance path P2 from the right to the conveyance merge unit 101, the sheet feeding device 10 is conveyed from any conveyance path. Even in the case of the sheet S, the sheet S can be stably conveyed upward in a state where the conveyance load on the sheet S is reduced. In addition, when the rotation fulcrum of the guide member 90 is not arrange | positioned at the center part of a longitudinal direction like this embodiment, it becomes difficult to ensure the movable range of the guide member 90 large as mentioned above.

  FIG. 7 is an enlarged cross-sectional view of a part of the image forming apparatus 1Z that is compared and referred to in the present embodiment. FIG. 8 is an enlarged cross-sectional view of a part of the conveyance joining portion 101Z of the image forming apparatus compared with the present embodiment. Referring to FIG. 8, the conveyance junction portion 101 </ b> Z includes a swing guide 95 that is referred to and compared with the guide member 90 of the present embodiment. The swing guide 95 is swingable about a fulcrum 951 disposed at the lower end. When the swing guide 95 is swung and the right guide surface 953, which is the right side surface of the swing guide 95, comes into contact with a contact wall 96 disposed inside the image forming apparatus 1Z, the swing guide 95 is moved. It is arranged on the rightmost side (95A in FIG. 8). In this case, the swing guide 95 guides the sheet S that has passed between the first paper feed roller 113Z and the counter roller 115Z upward. The left guide surface 952 that is the left side surface of the swing guide 95 is disposed along the second wall portion 151Z. On the other hand, when the left guide surface upstream portion 95S of the swing guide 95 abuts on the guide portion 118AZ due to the swing, the swing guide 95 is disposed on the leftmost side (95B in FIG. 8). In this case, the swing guide 95 guides the sheet S that has passed between the second paper feed roller 114Z and the counter pad 117Z upward. At this time, the right guide surface 953 of the swing guide 95 is disposed along the first wall 150Z.

  As described above, when the swing guide 95 is swung around the fulcrum 951 disposed at the lower end of the swing guide 95, the swing point 951 is separated from the upper end of the swing guide 95. The movable range of the guide 95 is narrowed. In FIG. 8, the angle formed by the left guide surface 952 of the swing guide 95A located on the rightmost side and the vertical direction is 11 degrees. The angle formed between the right guide surface 953 of the swing guide 95B located on the leftmost side and the vertical direction is 25.8 degrees. In other words, the angle formed by the two sheet conveying directions switched by the swing guide 95 is 36.8 degrees. Further, in the case as shown in FIG. 8, when the sheet S that has passed between the first paper feed roller 113Z and the opposing roller 115Z is conveyed toward the swing guide 95A, the left guide surface upstream of the swing guide 95A. A gap is formed between the portion 95S and the guide portion 118AZ. On the other hand, in the present embodiment, as shown in FIG. 5, at the first position 90A of the guide member 90, the left guide surface upstream portion 90S is arranged to be continuous with the guide portion 118A. For this reason, the sheet S is stably guided as compared with the embodiment shown in FIG.

  Furthermore, in the present embodiment, even when the sheet S is jammed in the conveyance junction 101, the sheet S is easily removed depending on the posture of the guide member 90. FIG. 6 is a cross-sectional view showing a state in which the housing opening / closing part 21A is opened in the image forming apparatus 1 according to the embodiment of the present invention. As shown in FIG. 6, the casing opening / closing part 21 </ b> A that is the right side portion of the lower casing 21 of the image forming apparatus 1 is rotatable about the lower part. A part of the sheet conveyance path PP is exposed to the outside of the lower casing 21 by the rotation of the casing opening / closing section 21A. In particular, the conveyance joining portion 101 is exposed by the rotation of the casing opening / closing portion 21A. Specifically, the wall portion 119 is separated from the guide member 90 by the rotation of the housing opening / closing portion 21A. For this reason, the downstream end of the second sheet conveyance path P <b> 2 is exposed to the outside of the lower housing 21. As a result, even when the sheet S2 is jammed in the second sheet conveyance path P2, the sheet S2 is easily removed. Further, as described above, the guide member 90 is disposed at the first position 90 </ b> A by the weight of the guide member 90. As a result, in FIG. 6, a region X that is a part of the first sheet conveyance path P1 and is located to the left of the guide member 90 at the first position 90A is exposed to the outside. Therefore, even if the sheet S2 or S3 conveyed through the second sheet conveyance path P2 and the third sheet conveyance path P3 is jammed on the right side of the guide member 90, the sheet conveyed through the first sheet conveyance path P1. Even when S1 is jammed on the left side of the guide member 90, the sheet S is easily removed.

  According to the embodiment described above, the guide member 90 guides the sheet S1 conveyed in the first direction along the first sheet conveyance path P1 in the first direction at the first position 90A. Further, the guide member 90 guides the sheet S2 conveyed in the second direction on the second sheet conveyance path P2 in the third direction at the second position 90B. The guide member 90 is rotated around a fulcrum portion 901 disposed at the center in the longitudinal direction. Therefore, when the conveyance path of the sheet S guided by the guide member 90 in the third direction is switched between the first sheet conveyance path P1 and the second sheet conveyance path P2, one end of the guide member 90 in the longitudinal direction is provided. Compared with the case where the fulcrum is arranged, a large movable range of the guide member 90 is ensured.

  Further, according to the above embodiment, when the guide member 90 is rotated around the fulcrum portion 901, the contact portion 901B of the guide member 90 is one of the first sheet conveyance path P1 and the second sheet conveyance path P2. Define the part. For this reason, the guide member 90 can suitably guide the sheet along the shape of the sheet conveyance path in which the conveyance direction is switched.

  Further, according to the above-described embodiment, the guide member 90 is stably disposed at the first position 90 </ b> A by its own weight or the urging force of the urging member provided on the fulcrum portion 901. For this reason, it is possible to accurately guide the sheet S1 conveyed through the first sheet conveyance path P1 in the third direction. Further, the guide member 90 moves from the first position 90 </ b> A to the second position 90 </ b> B when the leading end of the sheet S <b> 2 conveyed through the second sheet conveyance path P <b> 2 contacts the guide member 90. For this reason, even in the state where the guide member 90 is disposed at the first position 90A, the sheet S2 conveyed through the second sheet conveyance path P2 can be accurately guided in the third direction.

  In addition, according to the above-described embodiment, the guide member 90 is reliably in the first position 90 </ b> A by the front end portion of the sheet S <b> 2 contacting the contact portion 90 </ b> P downstream (upward) in the second direction from the fulcrum portion 901. To the second position 90B.

  Further, according to the above-described embodiment, since the wall portion 119 is separated from the guide member 90 in the open state of the housing opening / closing portion 21A, a part of the second sheet conveyance path P2 is outside the lower housing 21. Opened. Further, by arranging the guide member 90 at the first position 90 </ b> A, a part of the first sheet conveyance path P <b> 1 is exposed to the outside of the lower housing 21. For this reason, even if the sheet S is jammed in the first sheet conveyance path P1 or the second sheet conveyance path P2 around the guide member 90, the sheet S is easily removed.

  In addition, according to the above-described embodiment, the guide member 90 moves the sheet S3 conveyed through the third sheet conveyance path P3 in the third direction (upward) in addition to the first sheet conveyance path P1 and the second sheet conveyance path P2. ).

  The sheet feeding device 10 and the image forming apparatus 1 according to the embodiment of the present invention have been described above. However, the present invention is not limited to this, and for example, the following modified embodiment can be taken.

  (1) In the above embodiment, the conveyance junction unit 101 has been described in a mode in which the three conveyance paths of the first sheet conveyance path P1, the second sheet conveyance path P2, and the third sheet conveyance path P3 are merged. However, the present invention is not limited to this. The conveyance junction unit 101 only needs to be a unit that joins a plurality of conveyance paths. In addition, the first sheet conveyance path P1, the second sheet conveyance path P2, and the third sheet conveyance path P3 are limited to a mode that extends from the cassette 110, the manual feed tray 240, and an unillustrated retrofitted sheet cassette, respectively. However, it is sufficient that the sheet is conveyed toward the conveyance junction unit 101.

  (2) In the above-described embodiment, the guide member 90 is described as being disposed at the first position 90A by its own weight, but the present invention is not limited to this. As described above, the guide member 90 may be disposed at the first position 90A as the standby position by the biasing member such as a helical spring, or may be the second position 90B or the second position as the standby position. It may be arranged at the third position 90C.

  (3) In the above-described embodiment, the guide member 90 is stopped at the first position 90A when the housing opening / closing part 21A is opened in FIG. It is not limited to this. FIG. 9 is a cross-sectional view of the image forming apparatus 1 when the housing opening / closing part 21A is opened in a modified embodiment of the present invention. In the present modified embodiment, the image forming apparatus 1 does not include the cover member 118 shown in FIG. As the housing opening / closing part 21A is opened, the guide member 90 is rotated to the right from the first position 90A by its own weight (retracted position). For this reason, the area | region X of the left side of the guide member 90 is open | released much more, and the removal property of the sheet | seat S is improved. Further, a projecting portion 96 is disposed on the lower end side of the housing opening / closing portion 21 </ b> A so as to face the guide member 90. A pair of the projecting portions 96 are disposed so as to face both end portions of the guide member 90 in the front-rear direction. When the housing opening / closing part 21 </ b> A is closed, the protrusion 96 comes into contact with the upper end of the guide member 90. As a result, the guide member 90 is moved from the retracted position to the first position 90A. It should be noted that the center of gravity of the guide member 90 and the shape of the projecting portion 96 are previously set so that the guide member 90 abuts against the projecting portion 96 by its own weight and is disposed at the first position 90A when the housing opening / closing portion 21A is closed. Is set.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Paper feeding apparatus 101 Conveyance merge part 11 Paper feeding part 110 Cassette (sheet stacking part)
111 Lift Plate 112 Pickup Roller 113 First Paper Feed Roller 114 Second Paper Feed Roller 115 Opposing Roller 116 Registration Roller Pair 117 Opposing Pad 117A Pad Base Material Part 117B Pad Tip Part 117C Pad Rubing Part 118 Cover Member 118A Guide Part 118B Protection Section 119 Wall section 12 Paper feeding device 120 Image forming section 121 Photosensitive drum 15 Merged conveyance path (fourth conveyance path)
150 First wall portion 151 Second wall portion 2 Main housing 21 Lower housing (housing)
21A Case opening / closing part (cover member)
21R Connection opening 22 Upper housing 23 Connection housing 240 Manual feed tray 241 Paper discharge portion 242 Paper discharge tray 90 Guide member 90A First position 90B Second position 90C Third position 90P Contact portion 90S Left guide surface upstream portion 901 fulcrum part 901A guide part 901B contact part (extension part)
902 Left guide surface 903 Right guide surface 96 Projection P1 First sheet conveyance path (first conveyance path)
P2 Second sheet conveyance path (second conveyance path)
P3 Third sheet conveyance path (third conveyance path)

Claims (7)

A housing,
A first transport path disposed in the housing and transporting the first sheet in a first direction;
A second transport path disposed in the housing, transported in a second direction intersecting the first direction, and joined to the first transport path;
A first position that is disposed at a joining portion of the first conveyance path and the second conveyance path and guides the first sheet in the first direction and a third direction intersecting the second direction; A guide member capable of changing a position between the first position and a second position for guiding the second sheet in the third direction intersecting the first direction and the second direction;
A cover member that is disposed to face the guide member, includes a wall portion that forms part of the second transport path with the guide member, and is openable and closable with respect to the housing. And
The guide member has an elongated shape when viewed in a cross section orthogonal to the sheet width direction of the first sheet, and includes a fulcrum portion disposed at or near the center of the elongated shape in the longitudinal direction, and the fulcrum The position can be changed by rotating around the part ,
In the open state of the cover member, the guide member is disposed at the first position, and a part of the first transport path is exposed to the outside of the housing.
As the cover member changes from the closed state to the open state, the guide member is rotated to a retracted position that exposes the first transport path to the outside of the housing, rather than the first position.
A protrusion disposed on the cover member, abutting against the guide member as the cover member changes from an open state to a closed state, and rotating the guide member from the retracted position to the first position; A sheet conveying apparatus comprising:   Among the guide members, a wall surface extending upstream in the third direction from the fulcrum portion is formed on the first conveyance path and the second conveyance path as the guide member rotates. The sheet conveying apparatus according to claim 1, wherein a part of the sheet conveying apparatus is defined. The guide member is disposed at the first position by its own weight or a biasing force of a biasing member provided at the fulcrum portion,
The guide member moves from the first position to the second position when a leading end portion of the second sheet conveyed through the second conveyance path contacts the guide member. The sheet conveying apparatus according to claim 1.   The sheet conveying apparatus according to claim 3, wherein the leading end portion of the second sheet is in contact with a wall surface of the guide member on the downstream side of the fulcrum portion. A sheet stacking unit on which the first sheet is stacked;
A manual feed tray on which the second sheet is placed;
The first conveyance path is a conveyance path that conveys the first sheet from the sheet stacking unit to the guide member,
It said second transport path, the sheet conveying device according to any one of claims 1 to 4, characterized in that a conveying path for conveying said second sheet from the manual feed tray to the guide member. A third conveyance path extending toward the guide member from between the first conveyance path and the second conveyance path;
The guide member further includes a third position between the first position and the second position and guiding the third sheet conveyed in the third conveyance path in the third direction. sheet conveying device according to any one of claims 1 to 5, characterized in that. A sheet conveying device according to any one of claims 1 to 6 ,
An image forming unit for forming an image on the first sheet and the second sheet;
A fourth conveyance path through which the first sheet or the second sheet guided in the third direction by the guide member is conveyed to the image forming unit;
An image forming apparatus comprising:

Images